Staking machine



June 21, 1966 sc oLz 3,256,722

STAKING MACHINE Filed Jan. 50, 1964 5 Sheets-Sheet 1 Z/l VE/WUR Henna/7 54270/2 14270 jig T June 21, 1966 H. SCHOLZ 3,256,722

STAKING MACHINE Filed Jan. 30, 1964 5 Sheets-Sheet 5 United States Patent 3,256,722 STAKHNG MACHINE Hermann Scholz, 1 Hoppestrasse, Regensburg, Germany Filed Jan. 30, 1964, Ser. No. 342,594 Claims priority, appiication Germany, Jan. 31, 1963, B 70,560 2 Claims. (Cl. 69-34) This invention relates to machines for softening leather and its object is to provide an improved and more efficient machine of this kind.

In known leather softening machines the leather to be treated is pulled between fixed interengaging softening tools which are usually in the form of blades and rolls, the leather being drawn between the tools in an undulating or wavy path so that it is softened in the process.

In known leather softening machines of this kind upper and lower softening tools were each fixed to a swinging arm, and the tools when in the closed position, in which they were interengaged, were disposed along an opening in a table over which the leather was drawn. The softening tools only had a comparatively narrow width so that considerable manoeuvring of the leather was necessary and the output of the machine was correspondingly restricted. Moreover, this machine was comparatively complicated in construction and therefore expensive.

In other known leather softening machines the leather was drawn between interengagingfixed rolls in a wavy or undulating path for the purpose of softening.

In consequence of the fact that in all known kinds of leather softening machines the softening tools were interengaged to a certain extent and were fixed, considerable damage was done to the leather, especially at the edge which was sometimes even torn.

The invention provides a softening machine capable of a high output and in which tearing or damage to the leather is substantially eliminated and which, moreover, is simple in construction and therefore less expensive to produce. This is achieved according to the invention in that at least one of the softening tools is given an oscillating movement perpendicular to the path of the leather. It is arranged that either the upper or the lower softening tool, or both tools together, are subjected to such an oscillating movement. In the most advantageous form the upper softening tool is provided with a vibrator or oscillating mechanism and the lower softening tool is fixed.

Resulting from the fact that the softening tools are oscillated in a direction transverse to the direction of movement of the leather, and advantageously this oscillating movement is both perpendicular to' and transverse to the surface of the leather in the form of an orbital movement, a rigid grip on the leather by the softening tools is prevented and a thorough softening of the leather as a result of the continual to and fro movement of the tool is achieved. As the result of this oscillating movement the depth of engagement of the upper tool with the fixed lower tool is continually changed at the oscillation frequency and to the extent of the oscillation amplitude, so that an elastic or resilient engagement is pro vided. As a result of these oscillations damage to or possible tearing of the leather is substantially prevented, and the leather is uniformly treated throughout its length and width. The softening tools may be made sufficiently long so that leather of all widths may be treated in a single operation. By employing a sufficiently high frequency of oscillation, for example, 3000 cycles per minute, the permissible feed of the leather may be kept at such a high rate that the output of the softening machine is substantially increased as compared with the older known machines.

3,256,722 Patented June 21, 1966 ice The invention consists of a leather softening machine having upper and lower interengaging softening tools, characterized by means to oscillate at least one of the softening tools in a direction transverse to the direction of movement of the leather.

Selected embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which-- FIGURE 1 shows a diagrammatic side view of uppe and lower softening tools separated from each other to allow leather to be inserted between them;

FIGURE 1A is a view, partly in section, of an oscillator used with one of the softening tools in FIGURE 1;

FIGURE 2 shows the softening tools of FIGURE 1 closed to engage the leather between them;

FIGURE 3 shows a modification, the tools being in the closed position;

FIGURE 4 illustrates the suspension of the crossbeam carrying the upper softening tool;

FIGURE 5 is a partial plan view of the machine;

FIGURE 6 is a diagrammatic side view of an alternative embodiment of softening tools, the tools being separated; and

FIGURE 7 is a view corresponding to FIGURE 6 with the tools closed.

Referring to FIGURES 1 to 5 the leather softening machine according to the first embodiment of the invention comprises traction rolls 1 and 2 by which the leather 3 in sheet form is fed or drawn in a longitudinal path through the machine. Guide rolls 5 and 6 are provided and these are preferably fitted with braking means (not shown), such as a hydraulic braking motor, a friction brake or the like, the braking means being preferably adjustable in order to impose a uniform tension on the leather being processed. Behind the rolls 5 and 6 is a table 4 over which the leather is drawn.

Between the traction rolls 1 and 2 and the braked guide rolls 5 and 6 is a fixed softening tool comprising two upwardly projecting blades 8 and 9 having a channel-like space 10 between them.

In the operative position shown in FIGURE 2 in which the rolls 2 and 6 and the upper softening tool are lowered, a blade 11 constituting the upper softening tool enters into the space 10 so that the upper and lower tools are interengaged, the leather 3 lying between them. The blade 11 is fixed to a cross-beam 12 along its whole length. I

Mounted upon the cross-beam 12 of the upper softening tool is a vibrator or oscillator 13, in the form of an orbital oscillator constituted by. an electric motor having eccentric fly weights 13 mounted on the two ends of its shaft (see also FIGURE 1A), to produce oscillation of the beam 12 and blade 11 in an orbit in a plane extending longitudinally of the channel-like space 10 and substantially normal to the fed leather sheet.

As a result of this orbital movement the cross-beam 12 oscillates vertically in the direction of the doubleheaded arrow 14 of FIGURE 4, and also oscillates transversely in the direction of the double-headed arrow 14' of FIGURE 5. When the leather 3 is being drawn in the wavy or undulating path between the upper and lower softening tools, as shown in FIGURE 2, the depth of engagement between the blade 11 and the blades 8 and 9 varies in rhythm with the oscillation and by an amount dependent upon the amplitude of the oscillation. In consequence the upper softening tool beats the leather 3 due to the fact that there is a rhythmic loosening and tensioning of the leather and thorough bending thereof between the softening blades 8 and 9. Additionally, the upper tool blade 11 executes a sideways movement due to the transverse component 14 of the orbital oscillation and this produces a smoothing effect.

In FIGURE 3 the lower fixed softening tool 7' is shown provided with three upwardly projecting blades 16, 17 and 18 separated by spaces 19 and 20, while the upper softening tool 12 is composed of two depending softening blades 21 and 22 which move into the spaces 19 and 20 in the operative position. Thevibrator or oscillator 13 is, as before, shown mounted on the crossbeam, indicated at 12', which is oscillated both vertically and horizontally in an orbital movement which is perpendicular to the direction of movement of the leather, Naturally, still more softening blades may be provided if desired in the upper and lower tools.

FIGURES 4 and show that the cross-beam 12 is supported at one end on a further beam 23 which is supported at its two ends by the frame 25 of the machine through interposed rubber buflers 24. The other end of the cross-beam 12 is supported in similar manner, but is not shown. Naturally the two end beams 23 may be supported by resilient means other than the rubber buffers shown.

The oscillation frequency is preferably not less than 3000 cycles per minute for a leather feeding speed of about 20 to 50 feet per minute.

Instead of oscillating the cross-beam 12 or 12' the lower softening tool 7 or 7 may be oscillated. It would also be possible to oscillate both the upper and lower tools simultaneously, in which case the oscillations of the two tools would have to be arranged in opposing phase.

In the embodiment shown in FIGURES 6 and 7 the leather also travels over a table 4 between guide rolls 5 and 6 and traction rolls 1 and 2 in the direction of the arrow 15. Between two side plates 26 disposed near the respective sides of the machine is a softening blade 27 and a smoother 28 provided with grooves 28' slanting outwardly from the middle; the smoother 28 is pivotally mounted at 31 and is provided with a clamp spring 29. The side plates 26 are coupled to a connecting rod 30 which is oscillated by means of an eccentric (not shown). By initially rotating the side plates 26 about the pivot point 33, the blade 27 and the clamp spring 29 are either opened as in FIGURE 6 or closed as in FIGURE 7 so that the leather 3 is clamped between the plate 27 and the spring 29.

In operation the spring clamp 29 is able to yield in case of unevenness in the thickness of the leather. There is a lower fixed softening tool 32 provided over which the leather is drawn. The complete upper tool assembly, comprising the upper softening blade 27, the smoother 28 and the spring clamp 29, is oscillated about the pivot 33 in the direction of the double-headed arrow 34 by the connecting rod 30 between the position shown in full lines and the position shown in dotted lines in FIGURE 7, the extent of the movement being such that the leather 3 is bent to a greater or lesser extent around the lower blade 32 during the whole of the oscillation cycle. The relative displacement of the smoother 28 and spring clamp 29 for opening and closing the tool may be carried out mechanically or hydraulically.

What I claim is:

1. A leather softening machine having means for feeding leather sheet in a longitudinal path, a pair of softening tools oppositely spaced apart and adapted to receive the fed sheet therebetween, of which a first tool has a longitudinal channel transversely of said path and into which the second tool projects, said second tool adapted to deflect the fed leather, one of said tools being movable in a plane extending longitudinally of said channel and substantially normal to the path of the fed leather sheet, and power-operated orbital oscillator means operatively connected with said one tool for oscillating the same in an orbital path in said plane.

2. A leather softening machine having spaced sets of rolls for feeding leather sheet in a longitudinal path, a pair of softening blades with leather-deflecting edges and oppositely spaced apart and adapted to receive the fed sheet therebetween, one blade of said pair being oscillatable about an axis transverse to said path for deflecting with its edge the leather about the edge of the other blade, a spring blade oscillatable with said one blade and adapted to clamp the fed leather sheet to the edge of said blade, and means for oscillating said one blade and said spring blade.

References Cited by the Examiner UNITED STATES PATENTS 139,442 5/1873 Watson 6934 1,744,420 1/1930 Stackpole 6934 2,590,194 3/1952 Maeser 6933 FOREIGN PATENTS 266,921 10/1913 Germany.

JORDAN FRANKLIN, Primary Examiner.

A. R. GUEST, Assistant Examiner. 

1. A LEATHER SOFTENING MACHINE HAVING MEANS FOR FEEDING LEATHER SHEET IN A LONGITUDINAL PATH, A PATH OF SOFTENING TOOLS OPPOSITELY SPACED APART AND ADAPTED TO RECEIVE THE FED SHEET THEREBETWEEN, OF WHICH A FIRST TOOL HAS A LONGITUDINAL CHANNEL TRANSVERSELY OF SAID PATH AND INTO WHICH THE SECOND TOOL PROJECTS, SAID SECOND TOOL ADAPTED TO DEFLECT THE FED LEATHER, ONE OF SAID TOOLS BEING MOVABLE IN A PLANE EXTENDING LONGITUDINALLY OF SAID CHANNEL AND 